The research will feature ruthenium(II) and ruthenium(III) ammines, and other low-spin d6 or d5 transition metals in combination with molecules of biochemical interest. Part of the effort will be devoted to studying the interaction of the metal centers with purine and pyrimidine bases including nucleotides and nucleosides. Compounds will be prepared, rates and affinities in solution determined, and the effect of metal coordination on the reactivity of the bases studied. This work has as its object specific complxation by metal ions of nucleic acids. Similar studies will be done with amino acids and peptides, the goal here being to attach metal ions to specific sites in a protein and to study electron transfer reactions of such complexes. Other work will deal with the chemistry of sulfur ligands, and with the effect of coordination on nucleophilic reactions and on the oxidation of ligands.